Hi @TeatroLirico I've only had the Maruszczyck a month, so I'm just getting to know it. First impressions are that the build quality is excellent - it looks, feels, and plays like a class instrument, although I think the specs are pretty much entry level. In terms of sound - it's a classic P bass, and it does that very well, but obviously it doesn't have the same range of tones as some basses. That said, I'm actually quite impressed with how much variation you do get from the tone pot. It's got the best sustain of any short scale I've played.
The Spector is also a quality instrument, and it's more versatile, tone-wise, plus it's very comfortable to play (great neck) and wear, with easy access to the upper frets (not that I need them very often, but we do have All Right Now in the setlist!). All that said, I've not 100% bonded with it, which I think is probably just a personal thing. The sound isn't quite as warm as the NS-94 I had when I played long scales, and I think subconsciously I was expecting a short scale version of that! I think basically I might not have worked out how to get the best sound out of it, especially in a band setting.
Be really interested to hear a review of the Acinonyx if you get one - I imagine a fretless version would be sublime!